Conventionally, testing devices in which a flow path for flowing a sample is formed have been used for the purposes of testing samples such as blood, DNA, foods, or beverages. As an example of a testing device, there has been disclosed a testing device including: a sample pad as a liquid receiving portion for receiving a test liquid; a conjugate pad in which the test liquid supplied from the sample pad undergoes a reaction; and a membrane film for flowing the test liquid supplied from the conjugate pad (see PTL 1). The conjugate pad contains a labeled antibody obtained by labeling an antibody with a pigment or the like. When supplied with a test liquid from the sample pad, the conjugate pad lets any antigen contained in the test liquid react with the labeled antibody, and supplies them to the membrane film. On the other hand, an antibody (capture antibody) for capturing the antigen is previously applied over a detection portion of the membrane film. The antigen contained in the test liquid supplied from the conjugate pad is captured at the detection portion in the state of being conjugated with the labeled antibody. As a result, a color is developed at the detection portion, which makes it possible to measure the antigen contained in the test liquid qualitatively or quantitatively by visually observing or measuring the degree of the color development.
In use of a testing kit for the purposes of simple in-vitro diagnoses or the like, it is requested to save the time taken for the testing in order to reduce the burdens on the doctor, the patient, etc. Hence, PTL 1 discloses adjusting a water absorption speed of a synthetic fiber constituting the conjugate pad, to thereby increase a spreading speed of the test liquid and save the testing time.